Even as modern research on mindfulness has expanded, debate continues with regard to the measurement and conceptualization of mindfulness. This divergence has manifested in a proliferation of different measurement approaches. The present research contributes to the advancement of mindfulness measurement by performing a Rasch model analysis of the psychometric properties of the short form of the Freiburg Mindfulness Inventory (FMI-14). This rigorous psychometric method belongs to the family item response theory and can be considered to be a set of approaches complementing classical test theory. The FMI-14 was administered to a nonclinical convenience sample of N = 1,452 German adults. Our data showed poor fit to the Rasch model. A reanalysis of the model excluding one particular misfitting item (number 13) yielded an acceptable fit for the originally proposed one-factorial solution to the Rasch model. However, a two-factorial solution with the subfacets “presence” and “acceptance” provided a better overall fit than the unidimensional solution. Some degree of differential item functioning could be observed both in the uni- and two-dimensional solution suggesting that potential exists for improving the measurement quality of the FMI-13. In line with the recent research, it is concluded that the FMI-13 should be considered as a two-dimensional rather than a unidimensional instrument.